Gimbal assembly for a magnetic head slider and a suspension for supporting and fixing the magnetic head slider

ABSTRACT

A suspension for supporting a magnetic head slider has a fixing section on which the magnetic head slider is to be fixed with an adhesive. This suspension has a partition pattern for partitioning the fixing section into a plurality of sections for receiving the adhesive.

FIELD OF THE INVENTION

The present invention relates to a suspension for supporting a magnetichead slider and to a head gimbal assembly (HGA) provided with thesuspension and the slider, used in a magnetic disk unit or amagneto-optical disk unit wherein the magnetic head slider opposes asurface of a rotating magnetic or magneto-optical disk with a very lowflying height so as to read and write information from and into thedisk.

DESCRIPTION OF THE RELATED ART

In the HGA, the suspension supports the magnetic head slider fixed nearits one end portion. In general, the fixing of the magnetic head sliderto the suspension will be made by means of a bonding resin such as anepoxy adhesive or an ultraviolet curing adhesive supplied between theslider and the suspension. For example, Ohe et al. (Japanese PatentUnexamined Publication No.6-215513) discloses an HGA structure with amagnetic head slider fixed to a suspension by means of a bondingadhesive.

However, such a fixing structure of the conventional HGA may introducedistortion to the magnetic head slider due to shrinkage upon curing ofthe adhesive. Namely, since the bonding resin has been coated over thewhole fixing surface of the slider, some kinds of bonding resin mayprovide distortions such as crown change (deflected deformation) due totheir cure shrinkage to the fixed slider.

Use of a bonding resin or an adhesive with a higher bonding strengthwill introduce a greater shrinkage to increase crown change.Furthermore, the amount of this crown change will depend upon theenvironment temperature of the slider and thus it is difficult toachieve CSS (Contact Start Stop) characteristics of the slider. Inparticular, a specific section of the fixing surface of the slider, towhich a load point projection (the reverse of a dimple) of thesuspension presses, should be formed in an undistorted shape. If thisspecific section deforms due to cure shrinkage of the bonding resin,stable constant flying characteristics of the slider can never beexpected.

Contrary to this, using of the bonding resin with a lower bondingstrength will introduce a smaller shrinkage but insufficient bondingstrength will cause the fixed slider easily to separate from thesuspension.

According to the above-mentioned fixing structure of the conventionalHGA, in addition, it is very difficult to adequately control the amountof the adhesive provided to the fixing section. In fact, the HGAstructure disclosed in Ohe et al. has a convex part for preventingoverflow of the adhesive at a section on the suspension, on which themagnetic head slider is to be adhered. However, during a bondingprocess, excess adhesive will overflow the convex part to the outside ofthe slider-fixing area on the suspension unless the providing amount andalso the providing position of the adhesive are precisely controlled.

Furthermore, according to the conventional HGA, since the load pointprojection presses the fixing surface of the slider through a flexureand the adhesive layer, the distance between the top of the load pointprojection and the slider's fixing surface will change in accordancewith dispersion or variation of the thickness of the adhesive layer.Thus, according to the conventional HGA, it is very difficult toregulate the slider to stay at a stable load point.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide asuspension for supporting a magnetic head slider and a HGA with thesuspension and the slider, whereby the magnetic head slider can be fixedto the suspension without deformation and distortion.

Another object of the present invention is to provide a suspension forsupporting a magnetic head slider and a HGA with the suspension and theslider, whereby stable constant flying characteristics of the magnetichead slider can be secured.

The present invention relates to a suspension for supporting a magnetichead slider, having a fixing section on which the magnetic head slideris to be fixed by means of adhesive. Particularly, according to theinvention, the suspension has a partition pattern for partitioning thefixing section into a plurality of sections for receiving the adhesive.

Since the fixing section of the suspension is partitioned to thesections by means of the partition pattern, the adhesive is separatelysupplied to each of the sections. Accordingly, crown change of theslider due to cure shrinkage of the adhesive can be effectivelysuppressed, and also the amount of the crown change due to theenvironment temperature of the slider can be minimized. Therefore,stable constant flying characteristics of the slider and CSS performancecan be expected. In addition, an adhesive with a higher bonding strengthcan be used without introducing any crown change, resulting in that astrong and reliable bonding can be always expected. Furthermore, sincethe providing position of the adhesive can be precisely controlled, notonly reliable bonding can be always obtained but also the bondingprocess can be very easily carried out.

It is preferred that the partition pattern partitions the fixing sectioninto the plurality of sections so that the adhesive applied to therespective sections are not mixed with each other. Thus, even ifdifferent kinds of adhesive are supplied to the respective sections,these adhesives will not be mixed with each other.

It is also preferred that the suspension further includes a peripheralpattern surrounding the partition pattern, and that each of the sectionshas at least one opening for flowing out excess adhesive applied to therespective sections into a region between the partition pattern and theperipheral pattern. Thus, the amount of the adhesive in the respectivesections can be automatically controlled and also the thickness of theadhesive can be controlled to a constant. Since the excess adhesivenever overflow into the outer region of bonding pads which will beelectrically connected with respective pads of the magnetic head slider,contamination of these bonding pads due to the adhesive can beeffectively prevented.

Preferably, at least one of the sections has a different size from oneof the remaining sections. If sizes of the respective sections areadjusted to adequate values depending upon a required bonding strengthfor the slider and upon the inherent property of the adhesive such asthe bonding strength performance, an optimum bonding can be expected.

It is preferred that the suspension further includes a flexure on whichthe partition pattern is formed, a load beam for supporting the flexure,and a load point projection formed on the load beam for pressing themagnetic head slider through the flexure, and that the partition patternhas a solid layer pattern at a position the load point projectionpresses. Therefore, the load point projection always presses the fixingsurface of the slider through the flexure and the solid layer pattern.As a result, the distance between the top of the load point projectionand the fixing surface of the slider will not change in accordance withdispersion or variation of the thickness of the adhesive layer and thusthe slider can be surely regulated to stay at a stable load point.

Preferably, the suspension further includes connection conductors to beelectrically connected to input/output terminals of the magnetic headslider. The connection conductors may be formed by a plurality of thinfilm layers, and the partition pattern is formed by at least one layerof the thin film layers. Therefore, the partition pattern can be formedin the same thin film pattern fabrication process as that of theconnection conductors and the bonding pads. Thus, no additionalfabrication process is necessary for forming the partition pattern.

The present invention also relates to a head gimbal assembly with amagnetic head slider, and a suspension for supporting and fixing themagnetic head slider at a fixing section. The suspension includes apartition pattern for partitioning the fixing section into a pluralityof sections for receiving at least one kind of adhesive. The magnetichead slider is fixed to the suspension by means of the adhesive suppliedin the sections. As selectively providing different adhesives havingdifferent characteristics to the respective sections, reliable andstable bonding which satisfies the required bonding performance can beeasily achieved. Also, since the sections are partitioned, it is veryeasy to confirm whether each kind of the adhesive has already beenprovided or not. Thus, easier operation and improved reliability forbonding can be expected.

The same kind of adhesive may be supplied to all the sections, ordifferent kinds of adhesive may be supplied to the respective sections.

Further objects and advantages of the present invention will be apparentfrom the following description of the preferred embodiments of theinvention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plane view illustrating a partial structure of asuspension in a preferred embodiment according to the present invention;

FIG. 2 shows a plane view illustrating a partial structure of a HGA witha magnetic head slider mounted on the suspension shown in FIG. 1;

FIG. 3 shows a plane view illustrating in detail a structure of the topportion of a flexure in the embodiment shown in FIG. 1;

FIG. 4 is a sectional view along a 4--4 line of FIG. 3;

FIG. 5 is a sectional view along a 5--5 line of FIG. 3; and

FIG. 6 is a sectional view along a 6--6 line of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a partial structure of the suspension in a preferredembodiment according to the present invention, and FIG. 2 illustrates apartial structure of the HGA with the magnetic head slider mounted onthe suspension shown in FIG. 1.

In these figures, reference numeral 10 denotes a resilient flexure forsupporting the magnetic head slider 11 at a tongue or a tab 10a formednear one end portion of the flexure, and 12 denotes a load beam forsupporting and fixing the flexure 10, respectively. A base end portionof the load beam 12 is fixed to a base plate (not shown). The magnetichead slider 11 is fixed on the tongue 10a by means of a bonding resin oran adhesive.

The flexure 10 is made, in this embodiment, of a stainless steel plate(for example SUS304TA) with a thickness of about 25 μm. As for leadlines, four connection conductors 13a-13d of a thin film conductivepattern are formed on the flexure 10. One end of each the connectionconductors 13a-13d are electrically connected to four respective bondingpads 14a-14d of a thin film conductive pattern, which pads are directlyconnected to input/output terminals formed on the magnetic head slider11 mounted on the top end portion of the flexure 10, and the otherrespective ends of the connection conductors 13a-13d are connected toexternal connection pads (not shown) to be connected to externalcircuits.

The load beam 12 is made, in this embodiment, of a stainless steel platewith a thickness of about 62-76 μm and supports the flexure 10 along itswhole length. Fixing of the flexure 10 to the load beam 12 is achievedby means of a plurality of welded spots 15 such as laser welded spots. Aload point projection (not shown in FIGS. 1 and 2) for pressing thefixing surface (surface used for fixing) of the slider 11 through theflexure 10 is formed on the load beam 12.

FIG. 3 illustrates in detail a structure of the top portion of theflexure 10, FIG. 4 is a sectional view along line 4--4 of FIG. 3, FIG. 5is a sectional view along line 5--5 of FIG. 3, and FIG. 6 is a sectionalview along line 6--6 of FIG. 3.

As mentioned above the connection conductors 13a--13d and the bondingpads 14a-14d are formed on the flexure 10. Also, as shown in FIG. 3, onthe fixing section of the slider 11, positioned at the top portion (onand around the tongue 10a) of the flexure 10, are formed a partitionpattern 30 for partitioning the fixing section into a plurality ofsections for receiving the adhesive and a peripheral pattern 31surrounding the partition pattern 30. Partition pattern 30 andperipheral pattern 31 are made as thin film conductive patterns and, inthis embodiment, are formed in the same fabrication process as that ofthe connection conductors 13a-13d and the bonding pads 14a-14d.

These thin film conductive patterns can be formed by a well known methodsimilar to the patterning method of forming a printed circuit board on athin metal plate.

As shown in FIG. 4, the thin film pattern of the connection conductors13a-13d is formed by sequentially depositing a polyimide layer 32 with athickness of about 5 μm (lower insulating material layer), a patternedCu layer 33 with a thickness of about 4 μm (conductors layer), and apolyimide layer 34 with a thickness of about 5 μm (upper insulatingmaterial layer) on the flexure 10 in this order. Although it is notshown, a Ni layer and an Au layer are sequentially deposited on the Culayer, and there is no upper insulating material layer within theregions of the bonding pads 14a-14d.

As shown in FIGS. 5 and 6, the thin film patterns of the partitionpattern 30 and the peripheral pattern 31 are formed by depositing apatterned Cu layer 35 with a thickness of about 4 μm on the flexure 10.The peripheral pattern 31 is in fact formed by depositing a polyimidelayer with a thickness of about 5 μm (lower insulating material layer)and a patterned Cu layer with a thickness of about 4 μm on the flexure10 in this order.

In this embodiment, as shown in FIG. 3, five sections 36a-36e forreceiving the adhesive are provided by means of the partition pattern30. These sections 36a-36e are partitioned so that the adhesive suppliedto the respective sections are not mixed with each other. In thisembodiment, the section 36a has a larger size than that of anothersections 36b-36e. The number, shape and size of the sections describedin this embodiment are a mere example and it is apparent that there arevarious modifications other than that shown in FIG. 3 according to thepresent invention.

According to the HGA of this embodiment, the fixing section of thesuspension, to which the slider 11 is fixed, is partitioned to thesections 36a-36e by means of the partition pattern 30, and the adhesive37 is separately supplied to each of the sections 36a-36e. Since theadhesive 37 is separately provided to the respective sections, crownchange of the slider 11 due to cure shrinkage of the adhesive 37 can beeffectively suppressed and also the amount of the crown change due tothe environment temperature of the slider can be minimized. Accordingly,stable constant flying characteristics and CSS performance of the slider11 can be expected. In addition, an adhesive with a higher bondingstrength can be used without introducing any crown change resulting thatthe strong and reliable bonding can be always expected. Furthermore,since providing position of the adhesive can be precisely controlled,not only reliable bonding can be always obtained but also the bondingprocess can be very easily carried out. Also, since the partitionpattern 30 and the peripheral pattern 31 are formed in the same thinfilm pattern fabrication process as that of the connection conductors13a-13d and the bonding pads 14a-14d, no additional fabrication processis needed for forming the partition pattern 30 and the peripheralpattern 31.

If sizes of the respective sections 36a-36e are adjusted to adequatevalues depending upon a required bonding strength for the slider andupon the inherent property of the adhesive such as the bonding strengthperformance, an optimum bonding can be expected.

In the aforementioned embodiment, the same kind of the adhesive issupplied to the sections 36a-36e. However, in modifications, differentkinds of adhesive may be supplied to the respective sections 36a-36e.For example, an adhesive which will introduce little amount of crownchange may be provided to the sections 36a-36c, a conductive adhesivesuch as that containing silver epoxy may be provided to the section 36dand a quick-drying adhesive such as an ultraviolet curing adhesive maybe provided to the section 36e. Selectively providing differentadhesives with different characteristics to the respective sections asdescribed above results reliable and stable bonding which satisfies therequired bonding performance to easily achieve. Since the sections36a-36e are separated from each other, the different adhesives providedto the respective sections will not be mixed with each other. Also,since the sections 36a-36e are partitioned, it is very easy to confirmwhether each kind of the adhesive has already provided or not yet. Thus,easier operation and improved reliability for bonding can be expected.

It is apparent that the above-mentioned assignment of the differentkinds of adhesives to the sections is a mere example and that variousmodifications can be achieved. There are various kinds of adhesiveshaving different characteristics. For example, bonding resinsrespectively having quick-curing characteristics, characteristicsintroducing little amount of crown change, high bonding strengthcharacteristics and conductivity are known. By adequately assigning andproviding these various kinds of adhesives to the sections, a HGA havinga slider fixed to a suspension with substantially no crown change andwith the reliable bonding strength can be obtained.

As shown in FIG. 3, an intermediate region 38 with a certain area isformed between the partition pattern 30 and the peripheral pattern 31and the partition pattern 30 is formed so that each of the sections36a-36e has at least one opening 39 (two or three openings in thisembodiment) for communicating with the intermediate region 38. Dividefor the openings 39, excess adhesive applied to the respective sections36a-36e can flow out to the intermediate region 38 so as toautomatically control the amount of the adhesive 37 in the respectivesections 36a-36e and also so as to control the thickness of the adhesive37 to be constant. Furthermore, since the excess adhesive never overflowinto the outer region of the bonding pats 14a-14d which will beelectrically connected with respective pads of the magnetic head slider,contamination of these bonding pads 14a-14d due to the adhesive can beeffectively prevented.

As shown in FIGS. 3 and 6, a solid layer pattern 40 is formed on theflexure 10, at a position to which the load point projection 12a of theload beam 12 is pressing. Therefore, the load point projection 12aalways presses the fixing surface of the slider through the flexure 10and the solid layer pattern 40. As a result, the distance between thetop of the load point projection 12a and the fixing surface of theslider 11 will not change in accordance with dispersion or variation ofthe thickness of the adhesive layer and thus the slider 11 can be surelyregulated to stay at a stable load point.

Many widely different embodiments of the present invention may beconstructed without departing from the spirit and scope of the presentinvention. It should be understood that the present invention is notlimited to the specific embodiments described in the specification,except as defined in the appended claims.

What is claimed is:
 1. A head gimbal assembly comprising a magnetic headslider, and a suspension for supporting and fixing said magnetic headslider at a fixing section, said suspension including a partitionpattern for partitioning said fixing section into a plurality ofsections for receiving different kinds of adhesive, the magnetic headslider being fixed to said suspension by means of the adhesive suppliedin said sections, wherein said kinds of adhesive are different in atleast one of curing speed, crown change produced, bonding strength, andconductivity.
 2. The head gimbal assembly as claimed in claim 1, whereinthe same kind of adhesive is supplied to some of said sections.
 3. Thehead gimbal assembly as claimed in claim 1, wherein said partitionpattern partitions said fixing section into the plurality of sections sothat the adhesive applied to the respective sections are not mixed witheach other.
 4. The head gimbal assembly as claimed in claim 1, whereinat least one of said sections has a different size from one of theremaining sections.
 5. The head gimbal assembly as claimed in claim 1,wherein said suspension includes a flexure on which said partitionpattern is formed, a load beam for supporting said flexure, and a loadpoint projection formed on said load beam for pressing said magnetichead slider through said flexure, and wherein said partition pattern hasa solid layer pattern at a position said load point projection presses.6. A suspension for supporting a magnetic head slider, having a fixingsection on which a magnetic head slider is to be fixed by means ofadhesive, said suspension comprising:a partition pattern forpartitioning said fixing section into a plurality of sections forreceiving the adhesive; and a peripheral pattern surrounding saidpartition pattern, each of said sections having at least one opening forflowing out excess adhesive applied to the respective sections into aregion between said partition pattern and said peripheral pattern. 7.The suspension as claimed in claim 6, wherein said partition patternpartitions said fixing section into the plurality of sections so thatthe adhesive applied to the respective sections are not mixed with eachother.
 8. The suspension as claimed in claim 6, wherein at least one ofsaid sections has a different size from one of the remaining sections.9. The suspension as claimed in claim 6, wherein said suspension furthercomprises a flexure on which said partition pattern is formed, a loadbeam for supporting said flexure, and a load point projection formed onsaid load beam for pressing the magnetic head slider through saidflexure, and wherein said partition pattern has a solid layer pattern ata position said load point projection presses.
 10. The suspension asclaimed in claim 6, wherein said suspension further comprises connectionconductors to be electrically connected to input/output terminals of themagnetic head slider, said connection conductors being formed by aplurality of thin film layers, and wherein said partition pattern isformed by at least one layer of said thin film layers.
 11. A suspensionfor supporting a magnetic head slider, having a fixing section on whicha magnetic head slider is to be fixed by means of adhesive, saidsuspension comprising:a partition pattern for partitioning said fixingsection into a plurality of sections for receiving the adhesive; andconnection conductors to be electrically connected to input/outputterminals of the magnetic head slider, said connection conductors beingformed by a plurality of thin film layers, said partition pattern beingformed by at least one layer of said thin film layers.
 12. Thesuspension as claimed in claim 11, wherein said partition patternpartitions said fixing section into the plurality of sections so thatthe adhesive applied to the respective sections are not mixed with eachother.
 13. The suspension as claimed in claim 11, wherein at least oneof said sections has a different size from one of the remainingsections.
 14. The suspension as claimed in claim 11, wherein saidsuspension further comprises a flexure on which said partition patternis formed, a load beam for supporting said flexure, and a load pointprojection formed on said load beam for pressing the magnetic headslider through said flexure, and wherein said partition pattern has asolid layer pattern at a position said load point projection presses.15. A head gimbal assembly comprising a magnetic head slider, and asuspension for supporting and fixing said magnetic head slider at afixing section, said suspension including:a partition pattern forpartitioning said fixing section into a plurality of sections forreceiving at least one kind of adhesive, said magnetic head slider beingfixed to said suspension by means of the adhesive supplied in saidsections; and a peripheral pattern surrounding said partition pattern,each of said sections having at least one opening for flowing out excessadhesive applied to the respective sections into a region between saidpartition pattern and said peripheral pattern.
 16. The head gimbalassembly as claimed in claim 15, wherein the same kind of adhesive issupplied to said sections.
 17. The head gimbal assembly as claimed inclaim 15, wherein different kinds of adhesive are supplied to some ofsaid sections, respectively.
 18. The head gimbal assembly as claimed inclaim 15, wherein said partition pattern partitions said fixing sectioninto the plurality of sections so that the adhesive applied to therespective sections are not mixed with each other.
 19. The head gimbalassembly as claimed in claim 15, wherein said suspension includes aperipheral pattern surrounding said partition pattern, and wherein eachof said sections has at least one opening for flowing out excessadhesive applied to the respective sections into a region between saidpartition pattern and said peripheral pattern.
 20. The head gimbalassembly as claimed in claim 15, wherein at least one of said sectionshas a different size from one of the remaining sections.
 21. The headgimbal assembly as claimed in claim 15, wherein said suspension includesa flexure on which said partition pattern is formed, a load beam forsupporting said flexure, and a load point projection formed on said loadbeam for pressing said magnetic head slider through said flexure, andwherein said partition pattern has a solid layer pattern at a positionsaid load point projection presses.
 22. The head gimbal assembly asclaimed in claim 15, wherein said suspension includes connectionconductors to be electrically connected to input/output terminals ofsaid magnetic head slider, said connection conductors being formed by aplurality of thin film layers, and wherein said partition pattern isformed by at least one layer of said thin film layers.
 23. A head gimbalassembly comprising a magnetic head slider, and a suspension forsupporting and fixing said magnetic head slider at a fixing section,said suspension including:a partition pattern for partitioning saidfixing section into a plurality of sections for receiving at least onekind of adhesive, said magnetic head slider being fixed to saidsuspension by means of the adhesive supplied in said sections; andconnection conductors to be electrically connected to input/outputterminals of said magnetic head slider, said connection conductors beingformed by a plurality of thin film layers, said partition pattern beingformed by at least one layer of said thin film layers.
 24. The headgimbal assembly as claimed in claim 23, wherein the same kind ofadhesive is supplied to some of said sections.
 25. The head gimbalassembly as claimed in claim 23, wherein different kinds of adhesive aresupplied to said sections, respectively.
 26. The head gimbal assembly asclaimed in claim 23, wherein said partition pattern partitions saidfixing section into the plurality of sections so that the adhesiveapplied to the respective sections are not mixed with each other. 27.The head gimbal assembly as claimed in claim 23, wherein at least one ofsaid sections has a different size from one of the remaining sections.28. The head gimbal assembly as claimed in claim 23, wherein saidsuspension includes a flexure on which said partition pattern is formed,a load beam for supporting said flexure, and a load point projectionformed on said load beam for pressing said magnetic head slider throughsaid flexure, and wherein said partition pattern has a solid layerpattern at a position said load point projection presses.